Zhejiang Guanyu Stainless Steel Tube Co., Ltd  
  Directory | Useful Tool | Sitemap | Contact US | Home

         

Properties

Factors Affect Wear and Galling






Galling, or cold welding is a form of severe adhesive wear. Adhesive wear occurs between two metal surface that are in relative motion and under sufficient load to permit the transfer of material. This is a solid-phase welding process. The load must be sufficient, during relative motion, to disrupt the protective oxide layer covering surface asperities of the metal and permit metal to metal contact. Under high stress and poor lubrication conditions, stronger bonds may form over a larger surface area. Large fragments or surface protrusions may be formed and the result is galling of the surfaces. Severe galling can result in the seizure of metal components.

Materials which are highly ductile or which possess low work-hardening rates tend to be prone to galling. Austenitic stainless steel show a tendency to gall under certain conditions.

Factors affect Wear and Galling
  • design,
  • applied load,
  • contact area and degree of movement,
  • lubrication,
  • environment,
  • material properties (surface finish, hardness and steel microstructure).

  • Design tolerances should provide sufficient clearance. The contact load on sliding components should be kept to a minimum, while the contact area should be maximised. In this situation, lubrication plays an important role and the design must ensure that adequate lubrication can be effectively delivered to the components in relative motion.


    Surface finish of components is important as highly polished (< 0.25 mm Ra) or very rough (> 1.5 mm Ra) surface increase the tendency for wear and galling. Smooth surface result in more contact. The small 'valleys' and 'asperities' on the smooth surface means that lubricant cannot be held in place between the surface and dislodged material is retained in close contact with the surface resulting in wear. Rough surface result in interlocking of asperities, which promote severe tearing and galling. Surface finishes between these extremes are therefore preferable.

    The hardness and microstructure of the material play an important role in adhesive wear and galling. A high hardness (obtained by work hardening) austenitic stainless steel and a stable oxide film can provide resistance to galling. Surface hardening treatment can also have the same effect.

    The microstructure can also reduce adhesive wear and cold welding, where there are two or more phases (austenitic with ferritic or austenitic with martensitic). A similar effect can result if the steel structure has dispersions of "particles" such as carbides, nitrides, sulphides etc embedded in it. Additions such as sulphur made to improve machinability in grades such as 303 (1.4305) and 416 (1.4005) can affect the behaviour of the steel. The inclusions formed (mainly manganese rich sulphides) act as solid lubricants in sliding contact and so these steel exhibit better galling resistance than the non treated 304 (1.4301) and 420 (1.4021) grades from which they are derived.

    The inducement of compressive stresses by shot peening has also been found to be beneficial.

       Stainless Steel Tubing, Nickel Alloy Tubing, Brass Alloy Tubing, Copper Nickel Pipe Material Grades


    Related References:
    1. Galling Resistance of Stainless Steel
    2. Factors Affect Wear and Galling
    3. Improve Wear and Galling Resistance of Stainless Steel
    4. Frictional Properties of Stainless Steel

    TubingChina.com All Rights Reserved

    Directory | Standard | Heat | Heat Exchanger | Temperature | Pressure | Corrosion | Hardness | Surface | Properties | Select Stainless Steel | Contact US

    Useful Tools:

    Stainless Steel Weight Calculator
    Metals Weight Calculator
    Nickel Alloy Weight Calculator
    Copper Brass Alloy Weight Calculator
    Copper Brass Alloy Sheet Plate Weight Calculator
    Sheet Plate Weight Calculator
    Hardness Conversion Calculator
    Hardness Conversion Chart
    Rockwell Brinell Vickers Shore Hardness Conversion Chart
    Conversion Calculator
    Length Weight Temperature Volume Pressure Calculater
    Pipe Working Pressure Calculator
    Pressure Conversion Converter
    Round Bar Size Calculator
    Gauge Sizes
    Sheet Metal Gauge
    Pipe Schedule
    Nominal Pipe Size
    ANSI Pipe Chart
    Inch to mm Chart
    Stainless Steel Pipe Sizes
    Stainless Steel Tubing Sizes Chart
    Stainless Steel L H Grade
    Stainless Steel Density
    Conversion of Stainless Steel
    Nickel Alloy Grades Comparison Material Grade Chart Carbon Steel
    Structural Steel Comparison Chart



    Main Products:

    BA Tube | AP Tube
    Condenser Tubes Tubing
    Stainless Steel Reheater Tube Superheater Tubes
    Stainless Steel U bend Tube
    Nickel Alloy U bend Tubes
    Copper Alloy U Bend Tubes
    Heat Exchanger Tube
    Super Duplex Pipe
    Nickel Alloy Tube
    Brass Alloy Tubing
    Copper Nickel Alloys Tubes
    Stainless Steel Hollow Tube
    Stainless Steel Oval Tubing
    Stainless Steel Square Tubing
    Stainless Steel Rectangular Tubing
    Stainless Steel Capillary Tube
    Duplex Stainless Steel Pipe
    Seamless Stainless Steel Tubing
    Corrugated Stainless Steel Tubing
    Stainless Steel Twisted Tube
    Polishing Stainless Steel Tubing
    Stainless Steel Aircraft Tube
    Stainless Steel Hydraulic Tubing
    Stainless Steel Instrumentation Tubing
    Stainless Steel Angle Iron Bar
    Stainless Steel Mechanical Tube
    Bright Annealing Stainless Tube
    Heat resistant Stainless Steel
    Stainless Steel Welded Pipe
    Extruded Serrated Finned Tubes Integral Finned Tubes / Extruded Aluminum Finned Tubes
    Brass Alloys Copper Nickel Alloy Integral Low Finned Tubes
    HFW High Frequency Welded Helical Spiral Serrated Finned Tubes
    Corrosion Resistant Stainless Steel
    Corrosion Resistance Stainless Steel

    Stainless Steel Tubing Pipe

    304 Stainless Steel Pipe
    304L Stainless Steel Pipe
    304H Stainless Steel Pipe
    304/304L Stainless Steel Tubing
    309S Stainless Steel Pipe
    310S Stainless Steel Pipe
    316L Stainless Steel Tubing
    316Ti Stainless Steel Tube
    317L Stainless Steel Pipe
    321 321H Stainless Steel
    347 347H Stainless Steel
    904L N08094 Seamless Tubes
    17-4 PH 630 UNS S17400 Stainless Steel
    253MA S30815 Stainless Steel Tube
    S31254 254 SMO Pipe
    S31803 Stainless Steel
    2205 Duplex Pipe Tubing
    S32101 Stainless Steel
    S32304 Stainless Steel
    2507 Super Duplex Pipe
    S32750 Super Duplex Pipe
    S32760 Super Duplex Steel
    1.4462 Stainless Steel Pipe
    ASTM A213 | ASTM A269
    ASTM A312 | ASTM A511
    ASTM A789 | ASTM A790
    ASTM B161 / ASME SB 161 | ASTM B111
    EN 10216-5
    ASTM A789 ASME SA 789 S31803 S32205 S32101 S32750 S32760 S32304 S31500 S31260 Seamless Tubes
    EN 10216-5 1.4462 1.4362 1.4162 1.4410 1.4501 Seamless Tubes
    Nickel Alloy Tubing:

    UNS N08020 Alloy 20 Tubing
    UNS N02200 Alloy 200 Tube
    UNS N02201 Alloy 201 Pipe
    UNS N04400 Monel 400 Tubing
    N06600 Inconel 600 Tube
    N06601 Inconel 601 Tubing
    N06625 Inconel 625 Tubes
    N08800 Incoloy 800 Tube
    N08810 Incoloy 800H Tube
    N08811 Incoloy 800HT Tubing
    UNS N08825 Incoloy 825 Pipe
    ASTM B622 N10276 C276 Tubing
    ASTM B622 N06022 Hastelloy C-22 Alloy Tubes
    C28000 Brass Seamless Tubes C44300 Brass Seamless Tubes
    C68700 Brass Seamless Tubes
    C70600 Copper Nickel Tubes
    C71500 Copper Nickel Tubes
    DIN 2391 Seamless Precision Steel Tubes
    EN 10305-1 E215 E235 E355 Seamless Precision Steel Tube Tubing Tubes
    DIN 2393 St28 St34.2 St37.2 St44.2 St52.3 Welded Precision Steel Tubes
    EN 10305-2 E195 E235 E355 Welded Cold Drawn Precision Steel Tube